package org.bouncycastle.cms.gm;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.DERNull;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.cryptopro.CryptoProObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.PBKDF2Params;
import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
import org.bouncycastle.asn1.pkcs.RC2CBCParameter;
import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
import org.bouncycastle.cms.CMSAlgorithm;
import org.bouncycastle.cms.CMSException;
import org.bouncycastle.cms.PasswordRecipient;
import org.bouncycastle.jcajce.util.AlgorithmParametersUtils;
import org.bouncycastle.operator.DefaultSecretKeySizeProvider;
import org.bouncycastle.operator.GenericKey;
import org.bouncycastle.operator.SecretKeySizeProvider;
import org.bouncycastle.operator.SymmetricKeyUnwrapper;
import org.bouncycastle.operator.jcajce.JceAsymmetricKeyUnwrapper;
import org.bouncycastle.operator.jcajce.JceKTSKeyUnwrapper;

import javax.crypto.*;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.RC2ParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.security.*;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;
import java.util.HashMap;
import java.util.Map;

/**
 * @author Songjin
 * @since 2021-10-03 11:40
 */
public class EnvelopedDataHelper {
    
    protected static final SecretKeySizeProvider KEY_SIZE_PROVIDER = DefaultSecretKeySizeProvider.INSTANCE;
    
    protected static final Map<ASN1ObjectIdentifier, String> BASE_CIPHER_NAMES = new HashMap<>();
    protected static final Map<ASN1ObjectIdentifier, String> CIPHER_ALG_NAMES  = new HashMap<>();
    protected static final Map<ASN1ObjectIdentifier, String> MAC_ALG_NAMES     = new HashMap<>();
    
    private static final Map<AlgorithmIdentifier, String> PBKDF2_ALG_NAMES = new HashMap<>();
    private static final short[]                          rc2Table         = {
            0xbd, 0x56, 0xea, 0xf2, 0xa2, 0xf1, 0xac, 0x2a, 0xb0, 0x93, 0xd1, 0x9c, 0x1b, 0x33, 0xfd, 0xd0,
            0x30, 0x04, 0xb6, 0xdc, 0x7d, 0xdf, 0x32, 0x4b, 0xf7, 0xcb, 0x45, 0x9b, 0x31, 0xbb, 0x21, 0x5a,
            0x41, 0x9f, 0xe1, 0xd9, 0x4a, 0x4d, 0x9e, 0xda, 0xa0, 0x68, 0x2c, 0xc3, 0x27, 0x5f, 0x80, 0x36,
            0x3e, 0xee, 0xfb, 0x95, 0x1a, 0xfe, 0xce, 0xa8, 0x34, 0xa9, 0x13, 0xf0, 0xa6, 0x3f, 0xd8, 0x0c,
            0x78, 0x24, 0xaf, 0x23, 0x52, 0xc1, 0x67, 0x17, 0xf5, 0x66, 0x90, 0xe7, 0xe8, 0x07, 0xb8, 0x60,
            0x48, 0xe6, 0x1e, 0x53, 0xf3, 0x92, 0xa4, 0x72, 0x8c, 0x08, 0x15, 0x6e, 0x86, 0x00, 0x84, 0xfa,
            0xf4, 0x7f, 0x8a, 0x42, 0x19, 0xf6, 0xdb, 0xcd, 0x14, 0x8d, 0x50, 0x12, 0xba, 0x3c, 0x06, 0x4e,
            0xec, 0xb3, 0x35, 0x11, 0xa1, 0x88, 0x8e, 0x2b, 0x94, 0x99, 0xb7, 0x71, 0x74, 0xd3, 0xe4, 0xbf,
            0x3a, 0xde, 0x96, 0x0e, 0xbc, 0x0a, 0xed, 0x77, 0xfc, 0x37, 0x6b, 0x03, 0x79, 0x89, 0x62, 0xc6,
            0xd7, 0xc0, 0xd2, 0x7c, 0x6a, 0x8b, 0x22, 0xa3, 0x5b, 0x05, 0x5d, 0x02, 0x75, 0xd5, 0x61, 0xe3,
            0x18, 0x8f, 0x55, 0x51, 0xad, 0x1f, 0x0b, 0x5e, 0x85, 0xe5, 0xc2, 0x57, 0x63, 0xca, 0x3d, 0x6c,
            0xb4, 0xc5, 0xcc, 0x70, 0xb2, 0x91, 0x59, 0x0d, 0x47, 0x20, 0xc8, 0x4f, 0x58, 0xe0, 0x01, 0xe2,
            0x16, 0x38, 0xc4, 0x6f, 0x3b, 0x0f, 0x65, 0x46, 0xbe, 0x7e, 0x2d, 0x7b, 0x82, 0xf9, 0x40, 0xb5,
            0x1d, 0x73, 0xf8, 0xeb, 0x26, 0xc7, 0x87, 0x97, 0x25, 0x54, 0xb1, 0x28, 0xaa, 0x98, 0x9d, 0xa5,
            0x64, 0x6d, 0x7a, 0xd4, 0x10, 0x81, 0x44, 0xef, 0x49, 0xd6, 0xae, 0x2e, 0xdd, 0x76, 0x5c, 0x2f,
            0xa7, 0x1c, 0xc9, 0x09, 0x69, 0x9a, 0x83, 0xcf, 0x29, 0x39, 0xb9, 0xe9, 0x4c, 0xff, 0x43, 0xab
    };
    private static final short[]                          rc2Ekb           = {
            0x5d, 0xbe, 0x9b, 0x8b, 0x11, 0x99, 0x6e, 0x4d, 0x59, 0xf3, 0x85, 0xa6, 0x3f, 0xb7, 0x83, 0xc5,
            0xe4, 0x73, 0x6b, 0x3a, 0x68, 0x5a, 0xc0, 0x47, 0xa0, 0x64, 0x34, 0x0c, 0xf1, 0xd0, 0x52, 0xa5,
            0xb9, 0x1e, 0x96, 0x43, 0x41, 0xd8, 0xd4, 0x2c, 0xdb, 0xf8, 0x07, 0x77, 0x2a, 0xca, 0xeb, 0xef,
            0x10, 0x1c, 0x16, 0x0d, 0x38, 0x72, 0x2f, 0x89, 0xc1, 0xf9, 0x80, 0xc4, 0x6d, 0xae, 0x30, 0x3d,
            0xce, 0x20, 0x63, 0xfe, 0xe6, 0x1a, 0xc7, 0xb8, 0x50, 0xe8, 0x24, 0x17, 0xfc, 0x25, 0x6f, 0xbb,
            0x6a, 0xa3, 0x44, 0x53, 0xd9, 0xa2, 0x01, 0xab, 0xbc, 0xb6, 0x1f, 0x98, 0xee, 0x9a, 0xa7, 0x2d,
            0x4f, 0x9e, 0x8e, 0xac, 0xe0, 0xc6, 0x49, 0x46, 0x29, 0xf4, 0x94, 0x8a, 0xaf, 0xe1, 0x5b, 0xc3,
            0xb3, 0x7b, 0x57, 0xd1, 0x7c, 0x9c, 0xed, 0x87, 0x40, 0x8c, 0xe2, 0xcb, 0x93, 0x14, 0xc9, 0x61,
            0x2e, 0xe5, 0xcc, 0xf6, 0x5e, 0xa8, 0x5c, 0xd6, 0x75, 0x8d, 0x62, 0x95, 0x58, 0x69, 0x76, 0xa1,
            0x4a, 0xb5, 0x55, 0x09, 0x78, 0x33, 0x82, 0xd7, 0xdd, 0x79, 0xf5, 0x1b, 0x0b, 0xde, 0x26, 0x21,
            0x28, 0x74, 0x04, 0x97, 0x56, 0xdf, 0x3c, 0xf0, 0x37, 0x39, 0xdc, 0xff, 0x06, 0xa4, 0xea, 0x42,
            0x08, 0xda, 0xb4, 0x71, 0xb0, 0xcf, 0x12, 0x7a, 0x4e, 0xfa, 0x6c, 0x1d, 0x84, 0x00, 0xc8, 0x7f,
            0x91, 0x45, 0xaa, 0x2b, 0xc2, 0xb1, 0x8f, 0xd5, 0xba, 0xf2, 0xad, 0x19, 0xb2, 0x67, 0x36, 0xf7,
            0x0f, 0x0a, 0x92, 0x7d, 0xe3, 0x9d, 0xe9, 0x90, 0x3e, 0x23, 0x27, 0x66, 0x13, 0xec, 0x81, 0x15,
            0xbd, 0x22, 0xbf, 0x9f, 0x7e, 0xa9, 0x51, 0x4b, 0x4c, 0xfb, 0x02, 0xd3, 0x70, 0x86, 0x31, 0xe7,
            0x3b, 0x05, 0x03, 0x54, 0x60, 0x48, 0x65, 0x18, 0xd2, 0xcd, 0x5f, 0x32, 0x88, 0x0e, 0x35, 0xfd
    };
    
    static {
        BASE_CIPHER_NAMES.put(CMSAlgorithm.DES_CBC, "DES");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.DES_EDE3_CBC, "DESEDE");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.AES128_CBC, "AES");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.AES192_CBC, "AES");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.AES256_CBC, "AES");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.RC2_CBC, "RC2");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.CAST5_CBC, "CAST5");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.CAMELLIA128_CBC, "Camellia");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.CAMELLIA192_CBC, "Camellia");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.CAMELLIA256_CBC, "Camellia");
        BASE_CIPHER_NAMES.put(CMSAlgorithm.SEED_CBC, "SEED");
        BASE_CIPHER_NAMES.put(PKCSObjectIdentifiers.rc4, "RC4");
        BASE_CIPHER_NAMES.put(CryptoProObjectIdentifiers.gostR28147_gcfb, "GOST28147");
        BASE_CIPHER_NAMES.put(GMObjectIdentifiers.sms4_ecb, "SM4");
        
        CIPHER_ALG_NAMES.put(CMSAlgorithm.DES_CBC, "DES/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.RC2_CBC, "RC2/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.DES_EDE3_CBC, "DESEDE/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.AES128_CBC, "AES/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.AES192_CBC, "AES/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.AES256_CBC, "AES/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(PKCSObjectIdentifiers.rsaEncryption, "RSA/ECB/PKCS1Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.CAST5_CBC, "CAST5/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.CAMELLIA128_CBC, "Camellia/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.CAMELLIA192_CBC, "Camellia/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.CAMELLIA256_CBC, "Camellia/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(CMSAlgorithm.SEED_CBC, "SEED/CBC/PKCS5Padding");
        CIPHER_ALG_NAMES.put(PKCSObjectIdentifiers.rc4, "RC4");
        CIPHER_ALG_NAMES.put(GMObjectIdentifiers.sms4_ecb, "SM4/ECB/PKCS5Padding");
        
        MAC_ALG_NAMES.put(CMSAlgorithm.DES_EDE3_CBC, "DESEDEMac");
        MAC_ALG_NAMES.put(CMSAlgorithm.AES128_CBC, "AESMac");
        MAC_ALG_NAMES.put(CMSAlgorithm.AES192_CBC, "AESMac");
        MAC_ALG_NAMES.put(CMSAlgorithm.AES256_CBC, "AESMac");
        MAC_ALG_NAMES.put(CMSAlgorithm.RC2_CBC, "RC2Mac");
        
        PBKDF2_ALG_NAMES.put(PasswordRecipient.PRF.HMacSHA1.getAlgorithmID(), "PBKDF2WITHHMACSHA1");
        PBKDF2_ALG_NAMES.put(PasswordRecipient.PRF.HMacSHA224.getAlgorithmID(), "PBKDF2WITHHMACSHA224");
        PBKDF2_ALG_NAMES.put(PasswordRecipient.PRF.HMacSHA256.getAlgorithmID(), "PBKDF2WITHHMACSHA256");
        PBKDF2_ALG_NAMES.put(PasswordRecipient.PRF.HMacSHA384.getAlgorithmID(), "PBKDF2WITHHMACSHA384");
        PBKDF2_ALG_NAMES.put(PasswordRecipient.PRF.HMacSHA512.getAlgorithmID(), "PBKDF2WITHHMACSHA512");
    }
    
    private final JcaJceExtHelper helper;
    
    EnvelopedDataHelper(JcaJceExtHelper helper) {
        this.helper = helper;
    }
    
    // static Object execute(org.bouncycastle.cms.jcajce.EnvelopedDataHelper.JCECallback callback) throws CMSException {
    //     try {
    //         return callback.doInJCE();
    //     } catch (NoSuchAlgorithmException e) {
    //         throw new CMSException("can't find algorithm.", e);
    //     } catch (InvalidKeyException e) {
    //         throw new CMSException("key invalid in message.", e);
    //     } catch (NoSuchProviderException e) {
    //         throw new CMSException("can't find provider.", e);
    //     } catch (NoSuchPaddingException e) {
    //         throw new CMSException("required padding not supported.", e);
    //     } catch (InvalidAlgorithmParameterException e) {
    //         throw new CMSException("algorithm parameters invalid.", e);
    //     } catch (InvalidParameterSpecException e) {
    //         throw new CMSException("MAC algorithm parameter spec invalid.", e);
    //     }
    // }
    
    String getBaseCipherName(ASN1ObjectIdentifier algorithm) {
        String name = BASE_CIPHER_NAMES.get(algorithm);
        
        if (name == null) {
            return algorithm.getId();
        }
        
        return name;
    }
    
    Key getJceKey(GenericKey key) {
        if (key.getRepresentation() instanceof Key) {
            return (Key) key.getRepresentation();
        }
        
        if (key.getRepresentation() instanceof byte[]) {
            return new SecretKeySpec((byte[]) key.getRepresentation(), "ENC");
        }
        
        throw new IllegalArgumentException("unknown generic key type");
    }
    
    public Key getJceKey(ASN1ObjectIdentifier algorithm, GenericKey key) {
        if (key.getRepresentation() instanceof Key) {
            return (Key) key.getRepresentation();
        }
        
        if (key.getRepresentation() instanceof byte[]) {
            return new SecretKeySpec((byte[]) key.getRepresentation(), getBaseCipherName(algorithm));
        }
        
        throw new IllegalArgumentException("unknown generic key type");
    }
    
    public void keySizeCheck(AlgorithmIdentifier keyAlgorithm, Key key)
            throws CMSException {
        int expectedKeySize = KEY_SIZE_PROVIDER.getKeySize(keyAlgorithm);
        if (expectedKeySize > 0) {
            byte[] keyEnc = null;
            
            try {
                keyEnc = key.getEncoded();
            } catch (Exception e) {
                // ignore - we're using a HSM...
            }
            
            if (keyEnc != null) {
                if (keyEnc.length * 8 != expectedKeySize) {
                    throw new CMSException("Expected key size for algorithm OID not found in recipient.");
                }
            }
        }
    }
    
    Cipher createCipher(ASN1ObjectIdentifier algorithm)
            throws CMSException {
        try {
            String cipherName = CIPHER_ALG_NAMES.get(algorithm);
            
            if (cipherName != null) {
                try {
                    // this is reversed as the Sun policy files now allow unlimited strength RSA
                    return helper.createCipher(cipherName);
                } catch (NoSuchAlgorithmException e) {
                    // Ignore
                }
            }
            return helper.createCipher(algorithm.getId());
        } catch (GeneralSecurityException e) {
            throw new CMSException("cannot create cipher: " + e.getMessage(), e);
        }
    }
    
    Cipher createRFC3211Wrapper(ASN1ObjectIdentifier algorithm)
            throws CMSException {
        String cipherName = BASE_CIPHER_NAMES.get(algorithm);
        
        if (cipherName == null) {
            throw new CMSException("no name for " + algorithm);
        }
        
        cipherName += "RFC3211Wrap";
        
        try {
            return helper.createCipher(cipherName);
        } catch (GeneralSecurityException e) {
            throw new CMSException("cannot create cipher: " + e.getMessage(), e);
        }
    }
    
    KeyAgreement createKeyAgreement(ASN1ObjectIdentifier algorithm)
            throws CMSException {
        try {
            String agreementName = BASE_CIPHER_NAMES.get(algorithm);
            
            if (agreementName != null) {
                try {
                    // this is reversed as the Sun policy files now allow unlimited strength RSA
                    return helper.createKeyAgreement(agreementName);
                } catch (NoSuchAlgorithmException e) {
                    // Ignore
                }
            }
            return helper.createKeyAgreement(algorithm.getId());
        } catch (GeneralSecurityException e) {
            throw new CMSException("cannot create key agreement: " + e.getMessage(), e);
        }
    }
    
    AlgorithmParameterGenerator createAlgorithmParameterGenerator(ASN1ObjectIdentifier algorithm)
            throws GeneralSecurityException {
        String algorithmName = BASE_CIPHER_NAMES.get(algorithm);
        
        if (algorithmName != null) {
            try {
                // this is reversed as the Sun policy files now allow unlimited strength RSA
                return helper.createAlgorithmParameterGenerator(algorithmName);
            } catch (NoSuchAlgorithmException e) {
                // Ignore
            }
        }
        return helper.createAlgorithmParameterGenerator(algorithm.getId());
    }
    
    AlgorithmParameters createAlgorithmParameters(ASN1ObjectIdentifier algorithm)
            throws NoSuchAlgorithmException, NoSuchProviderException {
        String algorithmName = BASE_CIPHER_NAMES.get(algorithm);
        
        if (algorithmName != null) {
            try {
                // this is reversed as the Sun policy files now allow unlimited strength RSA
                return helper.createAlgorithmParameters(algorithmName);
            } catch (NoSuchAlgorithmException e) {
                // Ignore
            }
        }
        return helper.createAlgorithmParameters(algorithm.getId());
    }
    
    public KeyGenerator createKeyGenerator(ASN1ObjectIdentifier algorithm)
            throws CMSException {
        try {
            String cipherName = BASE_CIPHER_NAMES.get(algorithm);
            
            if (cipherName != null) {
                try {
                    // this is reversed as the Sun policy files now allow unlimited strength RSA
                    return helper.createKeyGenerator(cipherName);
                } catch (NoSuchAlgorithmException e) {
                    // Ignore
                }
            }
            return helper.createKeyGenerator(algorithm.getId());
        } catch (GeneralSecurityException e) {
            throw new CMSException("cannot create key generator: " + e.getMessage(), e);
        }
    }
    
    AlgorithmParameters generateParameters(ASN1ObjectIdentifier encryptionOID, SecretKey encKey, SecureRandom rand)
            throws CMSException {
        try {
            AlgorithmParameterGenerator pGen = createAlgorithmParameterGenerator(encryptionOID);
            
            if (encryptionOID.equals(CMSAlgorithm.RC2_CBC)) {
                byte[] iv = new byte[8];
                
                rand.nextBytes(iv);
                
                try {
                    pGen.init(new RC2ParameterSpec(encKey.getEncoded().length * 8, iv), rand);
                } catch (InvalidAlgorithmParameterException e) {
                    throw new CMSException("parameters generation error: " + e, e);
                }
            }
            
            return pGen.generateParameters();
        } catch (NoSuchAlgorithmException e) {
            return null;
        } catch (GeneralSecurityException e) {
            throw new CMSException("exception creating algorithm parameter generator: " + e, e);
        }
    }
    
    AlgorithmIdentifier getAlgorithmIdentifier(ASN1ObjectIdentifier encryptionOID, AlgorithmParameters params)
            throws CMSException {
        ASN1Encodable asn1Params;
        if (params != null) {
            try {
                asn1Params = AlgorithmParametersUtils.extractParameters(params);
            } catch (IOException e) {
                throw new CMSException("cannot extract parameters: " + e.getMessage(), e);
            }
        } else {
            asn1Params = DERNull.INSTANCE;
        }
        
        return new AlgorithmIdentifier(encryptionOID, asn1Params);
    }
    
    public KeyFactory createKeyFactory(ASN1ObjectIdentifier algorithm)
            throws CMSException {
        try {
            String cipherName = BASE_CIPHER_NAMES.get(algorithm);
            
            if (cipherName != null) {
                try {
                    // this is reversed as the Sun policy files now allow unlimited strength RSA
                    return helper.createKeyFactory(cipherName);
                } catch (NoSuchAlgorithmException e) {
                    // Ignore
                }
            }
            return helper.createKeyFactory(algorithm.getId());
        } catch (GeneralSecurityException e) {
            throw new CMSException("cannot create key factory: " + e.getMessage(), e);
        }
    }
    
    public JceAsymmetricKeyUnwrapper createAsymmetricUnwrapper(AlgorithmIdentifier keyEncryptionAlgorithm, PrivateKey keyEncryptionKey) {
        return helper.createAsymmetricUnwrapper(keyEncryptionAlgorithm, keyEncryptionKey);
    }
    
    public JceKTSKeyUnwrapper createAsymmetricUnwrapper(AlgorithmIdentifier keyEncryptionAlgorithm, PrivateKey keyEncryptionKey, byte[] partyUInfo, byte[] partyVInfo) {
        return helper.createAsymmetricUnwrapper(keyEncryptionAlgorithm, keyEncryptionKey, partyUInfo, partyVInfo);
    }
    
    public SymmetricKeyUnwrapper createSymmetricUnwrapper(AlgorithmIdentifier keyEncryptionAlgorithm, SecretKey keyEncryptionKey) {
        return helper.createSymmetricUnwrapper(keyEncryptionAlgorithm, keyEncryptionKey);
    }
    
    public AlgorithmIdentifier getAlgorithmIdentifier(ASN1ObjectIdentifier macOID, AlgorithmParameterSpec paramSpec) {
        if (paramSpec instanceof IvParameterSpec) {
            return new AlgorithmIdentifier(macOID, new DEROctetString(((IvParameterSpec) paramSpec).getIV()));
        }
        
        if (paramSpec instanceof RC2ParameterSpec) {
            RC2ParameterSpec rc2Spec = (RC2ParameterSpec) paramSpec;
            
            int effKeyBits = ((RC2ParameterSpec) paramSpec).getEffectiveKeyBits();
            
            if (effKeyBits != -1) {
                int parameterVersion;
                
                if (effKeyBits < 256) {
                    parameterVersion = rc2Table[effKeyBits];
                } else {
                    parameterVersion = effKeyBits;
                }
                
                return new AlgorithmIdentifier(macOID, new RC2CBCParameter(parameterVersion, rc2Spec.getIV()));
            }
            
            return new AlgorithmIdentifier(macOID, new RC2CBCParameter(rc2Spec.getIV()));
        }
        
        throw new IllegalStateException("unknown parameter spec: " + paramSpec);
    }
    
    SecretKeyFactory createSecretKeyFactory(String keyFactoryAlgorithm)
            throws NoSuchProviderException, NoSuchAlgorithmException {
        return helper.createSecretKeyFactory(keyFactoryAlgorithm);
    }
    
    byte[] calculateDerivedKey(int schemeID, char[] password, AlgorithmIdentifier derivationAlgorithm, int keySize)
            throws CMSException {
        PBKDF2Params params = PBKDF2Params.getInstance(derivationAlgorithm.getParameters());
        
        try {
            SecretKeyFactory keyFact;
            
            if (schemeID == PasswordRecipient.PKCS5_SCHEME2) {
                keyFact = helper.createSecretKeyFactory("PBKDF2with8BIT");
            } else {
                keyFact = helper.createSecretKeyFactory(PBKDF2_ALG_NAMES.get(params.getPrf()));
            }
            
            SecretKey key = keyFact.generateSecret(new PBEKeySpec(password, params.getSalt(), params.getIterationCount()
                                                                                                    .intValue(), keySize));
            
            return key.getEncoded();
        } catch (GeneralSecurityException e) {
            throw new CMSException("Unable to calculate derived key from password: " + e.getMessage(), e);
        }
    }
    
    interface JCECallback {
        Object doInJCE()
                throws CMSException, InvalidAlgorithmParameterException, InvalidKeyException, InvalidParameterSpecException,
                NoSuchAlgorithmException, NoSuchPaddingException, NoSuchProviderException;
    }
}
